Conversations on the Plurality of Worlds

Conversations on the Plurality of Worlds () is a work of astronomical and philosophical popular science in the form of a dialogue, published anonymously in 1686 and attributed to Bernard Le Bovier de Fontenelle. The text presents the astronomical theories of René Descartes and Nicolaus Copernicus through conversations between a narrator and a marquise, divided into six evenings and preceded by a preface and a dedication To Monsieur L***.

The book was intended for educated non-specialist readers, especially from aristocratic and fashionable society. Fontenelle's choice of French rather than scientific Latin helped the work reach a non-specialist audience: Conversations went through many new editions—33 during the author's lifetime—and was translated into more than ten languages.

Publication history

Composition and publication The work was published anonymously in 1686. The first edition contained five "evenings"; a sixth was added in the 1687 edition. During Fontenelle's lifetime, 33 editions of the text appeared.

Scientific and cultural context

The theme of the cosmic pluralism was already present in ancient philosophy: Epicurus, in the Letter to Herodotus, accepted the existence of innumerable worlds. At the end of the 16th century, Giordano Bruno, in On the Infinite Universe and Worlds, defended the idea of an infinite universe populated by inhabited worlds.

At the end of the 17th century, the Copernican system was not yet universally accepted, and educated readers remained more familiar with the geocentric system of Ptolemy. The Entretiens were among the first works to popularise Copernican and Cartesian ideas in French.

Dissemination and translations Translations published between the late 17th century and the 18th century show the European spread of the work. The first English translation, titled A Discourse of the Plurality of Worlds, was published in Dublin by Sir William Donville or Domville in 1687. The second translation, by Aphra Behn, appeared in 1688 under the title A Discovery of New Worlds and the third, by John Glanvill, later in 1688, titled A Plurality of Worlds. All three are translations of the first edition (1686). Fontenelle added more material in the second edition (1687). Elizabeth Gunning translated a later edition into English in 1803 as Conversations on the Plurality of Worlds.

The first printed Italian translation was published in Paris in 1748 by Annibale Antonini.

Structure The work is arranged as a series of evening conversations between a narrator and a marquise in a garden. Through dialogue, Fontenelle introduces astronomical themes gradually, alternating the narrator's explanations with examples and the marquise's objections.

The tone of the conversation alternates between scientific explanation, galanterie, and irony. Fontenelle often uses images drawn from everyday life and fashionable society to explain astronomical phenomena and philosophical concepts.

The division into six "evenings" combines the model of the philosophical and scientific dialogue with the forms of aristocratic conversation in the 17th century.

Contents

In the first evening, the narrator introduces the Copernican system: the Earth is not motionless at the centre of the universe, but is a planet that turns on its axis and revolves around the Sun. Fontenelle presents this change of perspective as an exercise in reasoning rather than as a technical demonstration, and invites the reader not to stop at the immediate appearance of the senses.

In the second evening, the Moon is described as an inhabited Earth. The argument is not presented as an observational certainty, but as a hypothesis based on analogy between celestial bodies. The comparison between the Earth and the Moon introduces the hypothesis that other celestial bodies may also be inhabited.

In the third evening, the discussion focuses on the characteristics of the lunar world and extends to the other planets. The narrator develops the hypothesis that the planets may be distinct worlds, each with its own physical conditions and inhabitants. The hypotheses about the inhabitants of other planets make the astronomical exposition more concrete and challenge the central role traditionally assigned to the Earth.

In the fourth evening, Fontenelle surveys Venus, Mercury, Mars, Jupiter, and Saturn, adapting to each planet considerations about size, distance from the Sun, and possible conditions of life. The explanation remains tied to Cartesian physics and presents the Solar System as an ordered set of worlds.

In the fifth evening, the fixed stars are interpreted as other suns, each capable of illuminating a world of its own. The planetary model is thus extended beyond the Solar System. This extension also has a philosophical meaning: the universe is not built around the Earth, and humanity loses the central position assigned to it by traditional cosmology.

In the sixth evening, added in 1687, Fontenelle returns to the preceding arguments in light of new celestial observations. The dialogue refers to recent astronomical observations and connects them with the hypothesis of the plurality of worlds. Many statements remain presented as hypotheses, but Fontenelle contrasts probable reasoning and observation with the authority of tradition.

Reception and criticism The success of the Entretiens sur la pluralité des mondes was "exceptional", and the work had already gone through 33 editions during Fontenelle's lifetime. Conversations was Fontenelle's best-known work and contributed to the spread of the Copernican system, which was still not universally accepted in 1686. The scientific knowledge on which the work was based was, however, limited, and some of its data were incorrect even for the time.

Marie-Françoise Mortureux noted that in 1686 the Journal des sçavans placed Fontenelle among writers on logic and physics; she nevertheless reads the Entretiens also as a literary text, not only as a scientific exposition. According to Mortureux, the dialogue is not a simple ornament: the marquise's questions and objections guide the explanation and translate scientific language into fashionable conversation. Marc Hersant, reviewing Fabrice Chassot's study of the scientific dialogue in the 18th century, presents the Entretiens as a point of reference for the 18th-century scientific dialogue, in which the explanation of science passes through a narrative and conversational situation.

Serge Hochedez interpreted the irony of the Entretiens as a means of critically examining traditional authorities and training the reader in the exercise of doubt. For Hochedez, the dialogue between the narrator and the marquise does not merely set out an astronomical system, but accustoms the reader to doubt and to distance from traditional authorities.

In her review of the critical edition prepared by Robert Shackleton, Suzanne Delorme noted that its introduction reconstructs both the Cartesian theory of vortices and the precedents represented by John Wilkins and Pierre Borel, adding that the scientific data used by Fontenelle in 1686 were far from exact. The historical interest of the work therefore lies above all in the way Fontenelle transformed an astronomical and philosophical debate into a conversation accessible to non-specialist readers.

The Entretiens were placed on the Index Librorum Prohibitorum in 1687; Giuseppe Tanzella-Nitti connects this measure with the cautions of 17th-century theological debate on the plurality of inhabited worlds.

Editions Partial list.

French editions

First edition, with five evenings. Described as the seventh edition.

Translations

Czech

Greek

English

Italian

Dutch

Polish

Portuguese

Russian

Spanish

Facsimile reprint of the 1914 edition.

Swedish

German

Conversations on the Plurality of Worlds

Bron en licentie